The present embodiments relate to medical diagnostic imaging. In particular, clipping is used in volume rendering.
Ultrasound or other medical imaging modalities may be used to scan a patient. For example, echocardiography is a commonly used imaging modality to visualize the structure of the heart. In 3D Echocardiography, images of the heart may be computed by a multi-planar reconstruction (MPR) or by volume rendering (VR). Standard views are captured to better visualize the cardiac structures. For example, in the apical four-chamber (A4C) view, all four cavities, namely left and right ventricles, and left and right atria, are present. In the apical two-chamber (A2C) view, only the left ventricle and the left atrium are present.
Ultrasound data may be acquired at a sufficient rate to allow three-dimensional ultrasound imaging in real-time. For example, a combination of one or more MPR's, which show images of specific planes through a 3-dimensional volume and a volume rendering (VR), which shows a 3-dimensional representation of a view of the data from a user-selectable viewing direction, is provided. Non-real-time three-dimensional ultrasound imaging may also be provided. In other examples, a VR is provided without an MPR.
The data may include information not desired in the VR. This information may occlude a region of interest in the image. To remove undesired information, a clipping plane may be used. Some systems provide for two clipping planes. The data representing locations on one side of a clipping plane or between two clipping planes is used for VR. However, insufficient clipping may result.
To view the selected portion of the volume from a different direction, the user changes the viewing direction. Changing between different view directions may cause a distracting or disorienting jump. User changes that incrementally change the clip plane or viewing direction may lack repeatability, preventing the user from consistently achieving the desired views.